Position indicator



July 1, 1958 G. PETERSON, JR

POSITION INDICATOR Filed Feb. 2l, 1957 3 therein operable to receive the arcuate armature member upon rotation of the armature in one direction, and a toroidal coil il is wound about the core member '38.' The solenoid 37 is formed in a manner similar to that of the solenoid 3o and also comprises a core and toroidal coil. A central opening 42 is provided in the core of the coil 37 operable to receive the armature member 24 upon rotation of the armature in the opposite direction. When the solenoid 36 is energized the arma-V ture member 25 will be pulled inwardly oi the central opening 39 of the armature 35 by means of the electromagnetic field created by the solenoid 36 and the indi cater will be rotated in the countercloclcwise direction relative to Fig. 2 from the central neutral position to one of its opposite limit positions. In a similar manner, when the solenoid 3d is deenergized and the solenoid 37 energized the armature member 24 will be pulled inwardly of the central opening 42 of the armature 37 rotating the armature and indicator assembly in the clockwise direction relative to Fig. 2 from the central neutral position toits opposite limit position.

The solenoids 36 and 37 are electrically connected with an external source of power by means of three electrically insulated conductors 43, 44 and 45 which extend through an externally threaded nipple 46 carried Vby the housing rear wall l5. The conductors 43, 44 and l5 extend outwardly beyond the nipple 46 and are engaged Within sockets of a conventional plug 47. The plug 47 is maintained in contact with the conductors by means of a knurled nut d8 engaging the plug 47 and threaded onto the nipple 45. Wires are soldered upon the inner end of the conductors 43, 44 and 45 and are electrically connected with the coils of the solenoid 36 and 37 as more fully described hereinafter.

Fig. 7 illustrates a schematic wiring diagram or the position indicator of the present invention wherein the indicator may be moved from its central neutral position to its opposite limit positions. The circuit illustrated in Fig. 9 is speciiically designed to indicate the position of the wheels of an aircraft and to this end, a pair of switches 51 and 52 are provided which may be closed by a switch actuating member 53 interconnected with the aircraft landing gear. When the switch Sl is closed the coil 36 will be energized thereby rotating the armature in the countercloclrwise direction relative to Fig. 2 to move the indicator to a position indicating the up position of the wheels. Alternatively, when the switch 52 is closed the armature 7 will be energized moving the indicator to a position indicating the down position of the wheels. When the indicator is in its central neutral position the wheels are midway between their up and down position and `both switches Si and SZ are opened. A resistor 54 may be provided in the electrical circuit and mounted interiorly of the housing of the position indicator. The resistor 54 will be used in series with the solenoids 36 and 37 when the position indicator is usedwith a conventional 110 volt power supply. lf the position indicator is to be used with a lower voltage power supply, for example, a 28 volt power supply which is common in most airplanes, the resistor 54:1 may be omitted from the circuit.

An important feature of the present invention is the provision of means on the side walls of the housing lli to properly position the armature and the indicator assembly within the housing To this end, the forward central portions of the side walls il, ll are indented as indicated at 56 in Figs. l and 4 of the drawings with generally U-shaped indentations directly opposite one another to provide generally U-shaped locating shoulders S7, 57 interiorly of the housing lil.

During assembly of the position indicator of the present invention when the rear wall of the indicator is being inserted in position at the rear of the casing 10 the iillister head bolts 3i, 3i which secure the forward ends of thel side frame members i6 and 17 together are received within the U-shaped locating shoulders 57, 57 formed interiorly of the housing side walls and thereby position and support the forward end of the side frame members 16 and i7 relative to the casing 10 and front Window M of the casing. By this construction, after the collet 34 has been adjusted to properly center the indicator 28 relative to the side frame members 16 and 17, the side frame members lo and i7 are positioned in the desired location relative to the window 14, so that the indicator is properly viewed through the window 14. After this position indicator has been completely assembled, a vacuum is created within the interior of the indicator by exhausting the air in the indicator through a tube 53 secured to the rear wall 15 and upon completion/of the lcrrnation of the vacuum the outer end of the tube 53 is sealed as shown at 59 in Fig. 2.

From the foregoing it will be observed that the present invention provides a novel position indicator having novel structural features whereby the position indicator be assembled rapidly and easily and maintained in the assembled position, and in which the indicator may be readily set at a central neutral position by a relatively simple adjustment prior to assembly. In addition, it will be observed that the present invention provides a novel position indicator which is of relatively simple construetion and may be manufactured and assembled easily and cheaply.

While particular embodiments of the present invention have been illustrated and described herein it is not intended to limit the invention to such a disclosure and changes and modifications may be incorporated and ernbodied therein within the scope of the following claims.

l claim:

l. An electro-magnetic indicator comprising a generally rectangular housing having front and side walls, a window in the front wall of said housing, a iirst side frame member for the indicator positioned Within said housing, a second side Iframe member carried by said first side frame member in spaced parallel relation therewith, mounting means to position said side frame members relative to said housing, an armature assembly pivotally mounted between said side frame members for rotary Y movement from a central neutral position to opposite limit positions, an indicator carried by said armature assembly adjacent said housing window operable to indicate the position of said armature, a centering spring operable to resiliently maintain said armature in its central neutral position, a spring retaining member carried by said armature, said retaining member mounted for adjusting movement with respect to the armature to permit adjustment of said central neutral position, and electro-magnetically operated actuators secured to said side frame members operable to actuate said armature assembly from said central position to said opposite limit positions.

2. An electro-magnetic indicator comprising a generally rectangular housing having front and side walls, a window in the front wall of said housing, a first side frame member for the indicator positioned within said housing, a second side frame member carried by said first side frame member in spaced parallel relation therewith, mounting means to position said side rframe members relative to said housing, an armature assembly pivotally mounted between said side frame members for rotary movement from a central neutral position to opposite limit positions, an indicator carried by said armature assembly adjacent said housing window operable to indicate the position of said armature, a centering spring one end thereof interconnected with said armature assembly and the other end thereof secured to side frame member operable to resiliently maintain said armature assembly in its central neutral position, a split collet frictionally engaging said armature assembly and secured to said one end of said `centering spring to permit adjustment of the central neutral position of said armature, and electromagnetically operated actuators secured to said side frame members operable to actuate said armature assembly from said central neutral position to said opposite limit positions.

3. An electro-magnetic indicator comprising a generally rectangular housing having front and side walls, a window in the front wall of said housing, a first side frame member for the indicator positioned within said Ihousing, a second side frame member carried by said first side frame member in spaced parallel relation therewith, means `forming generally U-shaped indentations projecting inwardly of said housing in opposite side walls thereof adjacent the housing front wall providing locating shoulders inwardly of said housing side walls, means interconnecting said frame members with said locating shoulders operable to position and support the forward ends of said side frame members, an armature assembly pivotally mounted between said side frame members for rotary movement from a central neutral position to opposite limit positions, an indicator carried by said armature assembly adjacent said housinfr window operable to indicate the position of said armature, a centering spring operable to resiliently maintain said armature in its central neutral position, means adjustably connecting one end of said centering spring to said armature assembly to permit adjustment of said central neutral position, and electromagnetically operated actuators secured to said side frame members operable to actuate said armature assembly from said central position to said opposite limit positions.

4. An electro-magnetic indicator comprising a generally rectangular housing having front and side walls, a window in the front wall of said housing, a first side frame member for the indicator positioned within said housing, a second side frame member carried by said rst side frame member in spaced parallel relation therewith, means forming generally U-shaped indentation projecting inwardly of said housing in opposite side walls thereof adjacent the housing front wall providing locating shoulders inwardly of said housing side walls, means interconnecting said side frame members with said locating shoulder operable to position and support the forward ends of said side frame met' bers, an armature assembly pivotally mounted between said side frame members for rotary movement rfrom a central neutral position to opposite limit positions, an indicator carried by said armature assembly adjacent said 'housing window operable to indicate the position of said armature, a centering spring having one end thereof interconnected with said armature assembly and the other end thereof secured to a side frame member operable to resiliently maintain said armature in its central neutral position, means adjustably connecting said one end of said centering spring to said armature assembly to permit adjustment of said central neutral position, and electromagnetically operated actuA ators secured to said side frame members operable to actuate said armature assembly from said central neutral position to said opposite limit positions.

5. In an electro-magnetic indicator of the type described, a housing having front and side walls, a window in the front wall of said housing, a rear wall fixedly secured to said housing completely `closing said housing, a first side frame member secured to said rear wall and projecting forwardly into said housing, a second side frame member carried by said iirst side frame member in spaced parallel relation therewith, means forming generally Ushaped indentation projecting inwardly of said housing in opposite side walls thereof adjacent the housing front wail providing locating shoulders inwardly of said housing side walls, and means interconnecting said side frame members with said locating shoulders operable to position and support the forward end of said side frame members.

References Cited in the tile of this patent UNITED STATES PATENTS 2,405,429 Jewell Aug. 6, 1946 

